Marc H. Taylor MSc.

Doctoral student, project CENSOR

Center for Tropical Ecology (ZMT)

Bremen, Germany

Exploration of marine zoning for Exploration of marine zoning for Bahía Sechura, PerúBahía Sechura, Perú

Study area: Study area: Bahía Sechura, Bahía Sechura, PerúPerú

~ 400 km2

► Rapid development of growout Rapid development of growout culture of the scallop culture of the scallop ArgopectenArgopecten purpuratuspurpuratus

Requires a shift in harvest rights Requires a shift in harvest rights from open-access to privatefrom open-access to private

Aquaculture is limited by seed Aquaculture is limited by seed availability availability

No information on the carrying No information on the carrying capacity of the system for capacity of the system for aquaculture enhancementaquaculture enhancement

Conflicts have begun to arise as to Conflicts have begun to arise as to how and where these zoning how and where these zoning changes are to be implementedchanges are to be implemented

The problem:The problem:

SechuraC hulliyach i

Palo Parado

M atacaballo

C onstante

P laya Las D elic ias

Parachique

Estuario de V irrilá

V ichayo

P to R ico

P ta Aguja

05° 30'

05° 33'

05° 36'

05° 39'

05° 42'

05° 45'

05° 48'

05° 51'

80° 45'80° 48'80° 51'80° 54'80° 57'81° 00'81° 0381° 06'

Ejem plares/m2

1 - 10

11 - 20

> 20

Presencia

► Identify „nucleii“ for scallop Identify „nucleii“ for scallop populationpopulation These will be left as an MPA for These will be left as an MPA for

spawning stock security.spawning stock security.

► Partition part of bay into culture area Partition part of bay into culture area

Proposal of fisheries ministryProposal of fisheries ministry

► Environmental variabilityEnvironmental variability Riverine input affects mortality Riverine input affects mortality

during El Nino.during El Nino. Riverine input may affect PP?Riverine input may affect PP? Strong PP from upwellingStrong PP from upwelling

► Advection pressesesAdvection presseses Available PP?Available PP? Settlement processes ?Settlement processes ?

Other Other considerationsconsiderations

► Cost / Benefits of zonationCost / Benefits of zonation Who will benefit?Who will benefit? How to maximize benefits?How to maximize benefits?

► MediationMediation River flow River flow PP PP Seed capture Seed capture Aquaculture Aquaculture

biomassbiomass O2 O2 scallop distribution scallop distribution

► 20 functional groups including 20 functional groups including DetritusDetritus 2 producer groups (2 producer groups (PhytoplanktonPhytoplankton and and MacroalgaeMacroalgae) ) ZooplanktonZooplankton 6 benthic primary consumer groups (6 benthic primary consumer groups (PolychaetesPolychaetes, , ScallopsScallops, , Sea urchinsSea urchins, ,

Herbivorous gastropodsHerbivorous gastropods, , Benthic detritivoresBenthic detritivores, and , and Miscellaneous filter Miscellaneous filter feedersfeeders))

6 benthic carnivore groups (6 benthic carnivore groups (Predatory gastropodsPredatory gastropods, , Small carnivoresSmall carnivores, , Predatory crabsPredatory crabs, , Sea starsSea stars, and , and OctopodsOctopods))

3 fish groups (3 fish groups (Littoral fishLittoral fish, , Small pelagic fishSmall pelagic fish, and , and Pelagic predatory fishPelagic predatory fish) ) 2 top predatory groups (2 top predatory groups (Marine mammalsMarine mammals and and Sea birdsSea birds). ).

► Additional changesAdditional changes Multistanza – scallopsMultistanza – scallops Aquaculture biomassAquaculture biomass Dummy groups – DO2, River input, SSTDummy groups – DO2, River input, SST

Base ModelBase Model

► To model the implementation of To model the implementation of several types of zoning several types of zoning strategies strategies

► Goal: Maximize user benefitsGoal: Maximize user benefits

EcospaceEcospace

► Sandy 0-10mSandy 0-10m► Sandy 10-20mSandy 10-20m► Silt 20-35mSilt 20-35m► +35m+35m► AquacultureAquaculture

HabitatsHabitats

5.35 °S

81.15 °W 80.80 °W

5.90 °S

Cell size: 0.01 x 0.01 deg

► Benthic resources Benthic resources confined to confined to habitats above habitats above 35m due to anoxic 35m due to anoxic conditions at lower conditions at lower depthsdepths

Defining habitatsDefining habitats

► Spawning stock Spawning stock (scallops)(scallops)

MPAsMPAs

5.35 °S

81.15 °W 80.80 °W

5.90 °S

► Fishing – all but aquaculture areasFishing – all but aquaculture areas► Diving – all areas +30m (may separate later into Diving – all areas +30m (may separate later into

open-access and Aquaculture)open-access and Aquaculture)► Seed Collection – sandy habitats (main recruitment Seed Collection – sandy habitats (main recruitment

habitat) plus aquaculture areashabitat) plus aquaculture areas► Aquaculture – aquaculture areasAquaculture – aquaculture areas► River – dummy mediation variable (forced with effort, River – dummy mediation variable (forced with effort,

E)E) Now linked only to PPNow linked only to PP

Rules for Fishery fleetsRules for Fishery fleets

ResultsResults

► Explore other MPA‘s (size and location) to enhance seed Explore other MPA‘s (size and location) to enhance seed availability / benefitsavailability / benefits

► Include Isla Lobos de Tierra – explore sources / sinks of scallop Include Isla Lobos de Tierra – explore sources / sinks of scallop populationspopulations Would require a third multistanza for advected scallop larvaeWould require a third multistanza for advected scallop larvae

ProspectsProspects

► ......

ProspectsProspects